Hello friends, I have a web application in dotnet core, which is microservice and mult-itenant. I want to add the ability to login with TON wallet. Its authentication system is openiddict outh 2. Is there an educational article on this topic?

Here's an example how TON login is implemented: https://docs.ton.org/develop/dapps/ton-connect/integration

I want to authenticate the user and set the permissions based on the database in the token returned from the server. So I need something unique like the public key of the wallet. Maybe I'm wrong. What unique information is available after the user's login to enable server-side authentication?
My application consists of several microservices and is SaaS (multi-tenant). This token, which is generated after login, must contain the necessary information about whole system

User's public key, wallet address, his signature on TonProof.

The manual shows how to check that TonProof is valid (on server side, of course).

Also, you should note that other servers can potentially get user's TonProof for your site if they use your manifest and user isn't careful enough to check that domain he connects the wallet to is incorrect.